Electrical box extension

ABSTRACT

An electrical box extension includes a base having a first edge, a second edge, an inner wall, and an outer wall. The inner wall defines an aperture. An annular flange is disposed on the inner wall. The flange has first and second support surfaces. A first receiving section is formed between the first edge and the upper support surface. A second receiving section is formed between the second edge and the second support surface. The extension is reversible for extending the electrical box in either a partially or fully extended position.

FIELD OF THE INVENTION

The present invention relates to an extension for an electrical box. Theextension enables a conventional electrical box, having a fixed depthand thus limited application, to be used with ceilings or walls ofvarious thicknesses up to one and a half inches. The extension isreversible for extending the electrical box to a partially extendedposition or a fully extended position.

BACKGROUND OF THE INVENTION

In new construction, electrical boxes are attached to supports prior toinstalling the surrounding wall or ceiling. Many electrical boxes areadapted to be attached to a joist, truss or other framing member. Wiringis run to the electrical box and housed within the electrical box. Oncethe electrical box is secured to the framing member and wired, thesurrounding ceiling or wall is formed of drywall and painted. A tool,such as a drywall saw, is then used to cut an opening in the ceiling orwall proximate the electrical box. Then, an electrical fixture, such asa ceiling fan or luminary fixture, is attached to the electrical box.

In some instances, electrical boxes used to support electrical fixturesare the same depth as the depth of the drywall forming the finishedsurface. In other words, the thickness of the box enables the box to beflush with the finished surface upon installation. One-half inch drywallis the most popular ceiling or wall covering. Consequently, typicalelectrical boxes have a depth of one-half inch. However, there are caseswhere the thickness of the drywall must be varied in order to act as asound barrier or to satisfy building code regulations for fireprotection (e.g. hotels, apartments, etc.). In these cases, installersare limited to using products that are specific to the drywallthickness, or a product that can be extended.

Most electrical boxes do not have ways for easily extending or modifyingtheir depth for use with varying ceiling or wall thicknesses. Forexample, U.S. Pat. No. 4,927,039 to McNab discloses an extender for anelectrical box having bores in corner blocks of the extender forreceiving fasteners to secure the extender to holes in the electricalbox. U.S. Pat. No. 5,975,323 to Turan discloses an adjustable extenderfor an electrical box having spacers positioned between the extender andthe electrical box to adjust the depth added to electrical box. U.S.Pat. No. 2,378,861 to Peevey and U.S. Pat. No. 2,989,206 to McAfeedisclose outlet box extensions having removable scored sections toadjust the depth added to the electrical box. Fasteners secure theextension to the electrical box. Lastly, U.S. Published PatentApplication Nos. 2003/0189043 to Wegner et al. and 2004/0051648 toHagarty et al. disclose electrical box extensions that are secured to anouter surface of the electrical box with fasteners.

These patents and applications are directed to extensions intended foruse primarily with fasteners. Moreover, these patents do not readilysimplify the extension of an electrical box.

Thus, there is a continuing need to provide improved electrical boxassemblies.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an extension and methodof assembling an extension with an electrical box which reduces thenumber of parts required, thus lowering inventory and storage costs.

Another object of the present invention is to provide an extension andmethod of assembling an extension with an electrical box without the aidof fasteners by utilizing an interference fit.

A further object of the present invention is to provide an extensionwhich is simple and inexpensive to manufacture, and easy to assemble anduse.

Yet another object of the present invention is to provide an extensionand method of assembling an extension with an electrical box in either apartially or fully extendable position by making the extensionreversible.

The foregoing objects are basically obtained by an extension adapted foruse with an electrical box having a base including a first edge, asecond edge, an inner wall, and an outer wall, the inner wall definingan aperture. A substantially annular shaped flange is disposed on theinner wall, the flange having first and second support surfaces. A firstreceiving section is formed between the first edge and the first supportsurface, and a second receiving section is formed between the secondedge and the second support surface.

The foregoing objects are also obtained by an electrical box assemblywith an electrical box including a side wall including an inner surfaceand outer surface. An extension having a base including a first edge, asecond edge, an inner wall, and an outer wall, the inner wall definingan aperture. A flange disposed on one of the inner or outer walls havingfirst and second support surfaces. The first receiving section is formedbetween the first edge and the first upper support surface, and a secondreceiving section is formed between the second edge and the secondsupport surface, each receiving section having a different depth fromone another. The extension is slidably engageable with the electricalbox side wall for mounting the electrical box in either a partiallyextended position or a fully extended position.

The foregoing objects are additionally obtained by a method of mountingan electrical box extension, comprising the steps of determining athickness of a ceiling or wall being installed. Connecting theelectrical box to a support. Installing the ceiling or wall adjacent thesupport. Locating the electrical box in the ceiling or wall. Cutting anaperture in the ceiling or wall for exposing the electrical box.Positioning one of a first receiving section or a second receivingsection of an extension contiguous to the electrical box depending uponthe thickness of the ceiling or wall. Slidably attaching the one of afirst receiving section or a second receiving section to the electricalbox.

Other objects, advantages, and salient features of the present inventionwill become apparent from the following detailed description, which,taken in conjunction with the annexed drawings, discloses preferredembodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings which form a part of this disclosure:

FIG. 1 is an exploded, bottom perspective view of an electrical box andextension according to the present invention.

FIG. 2 is an exploded, side elevational view in longitudinal section ofthe extension and electrical box of FIG. 1, depicting the electrical boxprior to insertion into a first receiving section in the extension.

FIG. 3 is a side elevational view in longitudinal section of theextension of FIG. 1, with the electrical box received in the firstreceiving section in the extension and the box and extension located ina ceiling or wall.

FIG. 4 is an exploded, side elevational view in longitudinal section ofthe extension and electrical box of FIG. 1, depicting the electrical boxprior to insertion into the second receiving section in the extension.

FIG. 5 is a side elevational view in longitudinal section of theextension of FIG. 1, with the electrical box received in the secondreceiving section in the extension and the box and extension located ina thicker ceiling or wall.

FIG. 6 is a side elevational view in longitudinal section of theextension according to a second embodiment of the invention engaging theinside and outside of the box.

FIG. 7 is a side elevational view in longitudinal section of theextension according to a third embodiment of the invention engaging theinside of the box.

FIG. 8 is a top plan view of the extension according to a fourthembodiment of the invention carrying breakaway supports for extrafasteners.

DETAILED DESCRIPTION OF THE INVENTION

Referring initially to FIGS. 1–5, an electrical box extension 30according to the present invention enables a conventional electrical box10, having a fixed depth and thus limited in application, to be usedwith ceilings or walls of various thicknesses up to one and a halfinches. The extension 30 is reversible for extending the electrical box10 to a partially extended position (FIG. 3) or a fully extendedposition (FIG. 5).

The electrical box 10 includes a substantially circular base 12 havingan upper surface 12 a, a lower surface 12 b, and a wiring chamber 14.The lower surface 12 b has a first substantially cylindrical inner wall16 extending substantially perpendicular therefrom. A secondsubstantially cylindrical outer wall 18 extends substantiallyperpendicular from the upper surface 12 a such that the first inner wall16 and second outer wall 18 are substantially concentric to a centrallydisposed axis of the base 12 defining an aperture 20 and a side walltherebetween. At least one opening 22 in the base 12 receives a firstfastener (e.g. a wood screw) for securing the electrical box 10 to asupport, such as a joist or truss. There are two openings 24,26 forreceiving at least two second fasteners to secure an electrical fixture(not shown) to the electrical box 10. Preferably, the second fasteners24,26 extend through the electrical box 10 into a truss or joist supportto firmly secure the electrical fixture to the support. The electricalbox 10 can be a ceiling box as disclosed in U.S. Pat. No. 6,722,621 toJohnson, the entire subject matter of which is hereby incorporated byreference. Preferably, the electrical fixture is a ceiling fan orluminaire. Moreover, preferably, the ceiling or wall is constructed ofdrywall 54, however, a suitable alternatives (e.g. plaster) may be used.

The extension 30 is adapted for use with the electrical box 10 andcomprises a substantially cylindrical base 32 including a first end edge34, a second end edge 36; an inner, substantially cylindrical, wall 38,and an outer substantially cylindrical wall 40. The inner wall 38 andouter wall 40 define an aperture 42. A substantially annular flange 44is positioned on the inner wall 38 and includes a first, substantiallyannular support surface 46 and a second, substantially annular supportsurface 48. A first receiving section 50 is formed between and by thefirst edge 34 and the first support surface 46. A second receivingsection 52 is formed between and by the second edge 36 and the secondsupport surface 48.

The base 32 of extension 30 is generally constructed of metal or plasticand has a substantially uniform transverse cross section. The base 32 ispreferably substantially annular, however, the base 32 may be formed ofany polygonal or combination of polygonal shapes. The base 32 has afirst or top edge 34 and a second or bottom edge 36. The first edge 34and second edge 36 are substantially annular and extend in planessubstantially parallel to one another. Each edge 34, 36 may be beveledand/or angled to facilitate engagement of the extension 30 with theelectrical box 10.

The base 32 includes a substantially annular inner wall 38 and asubstantially annular outer wall 40. The inner wall 38 establishes aninterference fit with the outer wall 18 of the electrical box 10. Theinner wall 38 and outer wall 40 are substantially concentric to thecentral axis of the base 32 and have generally smooth surfaces. Theinner wall 38 and outer wall 40 extend continuously between the top edge34 and the bottom edge 36 and define the central aperture 42. Theaperture 42 is preferably substantially annular, however, the aperture42 can be formed in the shaped of any polygon or combination ofpolygons.

The inner wall 38 or outer wall 40 can include notches for facilitatingengagement with a specific electrical box. Moreover, ribs can also beprovided along a surface of the inner wall 38 or outer wall 40 forproviding structural strength to the body at known points of increasedstress. The inner wall 38 or outer wall 40 may also be inwardly oroutwardly tapered for facilitating the interference fit engagement withthe electrical box 10.

The metal or plastic flange 44 is disposed on the inner wall 38.Preferably, the flange 44 has a substantially rectangular cross-section,however, the flange 32 can be of any polygonal shape or combination ofpolygonal shapes. The flange has a first mounting surface 46 and asecond mounting surface 48. A substantially L-shaped engagement lip isformed between both the first mounting surface 46 and the secondmounting surface 48 and the inner wall 38.

Preferably, the flange 44 continuously extends along the periphery ofthe inner wall 38; however, the flange 44 can be discontinuous andformed of spaced segments. The flange 44 can be integrally molded to thebase 32 or can alternatively be connected utilizing conventionalfasteners. Lastly, the first mounting surface 46 and/or the secondmounting surface 48 can have locating grooves disposed thereon forfacilitating positioning of the electrical box 10.

As best seen in FIGS. 3 and 5, a first receiving section 50 is formedbetween the first edge 34, the inner wall 38, and the first mountingsurface 46. The first receiving section 50 is adapted for extending theelectrical box 10 to a predetermined depth. A second receiving section52 is formed between the second edge 36, the inner wall 38, and thesecond mounting surface 48. The depth of the first receiving section 50is greater than that of the second receiving section 52.

As best seen in FIG. 3, the electrical box 10 is received in the firstreceiving section 50 and is partially extended to a distance t₁ (t₁=1.0in). FIG. 2 also illustrates the length of individual components, a, b,c, d, and e. The components, a, b, c, d, and e correspond tosubstantially about the following lengths/depths in inches: a=1.0 in.;b=0.5 in.; c=0.25 in.; d=0.25 in.; e=0.5 in. Thus, when the electricalbox 10 nests within the first receiving section 50, the electrical box10 is extended 0.5 inches (c+d). Therefore, the electrical box 10 isextended to t₁ of about 1.0 inch. Preferably, the drywall 54 thicknesswill also be substantially about t₁ or 1.0 in. However, presentelectrical codes allow 0.25 in. of non-combustible drywall 54 materialsto be exposed beyond the electrical box 10, so the drywall thickness 54may also extend up to 0.25 inches beyond the extension 30, effectivelyextending the electrical box 10 to use with walls of about 1.25 inchesin thickness.

As best seen in FIG. 5, the electrical box 10 is received in the secondreceiving section 52 and is fully extended to a distance t₂ (t₂=1.25in). FIG. 4 also illustrates the length of individual components, a, b,c, d, and e. As noted above, the components, a, b, c, d, and ecorrespond to substantially about the following lengths/depths: a=1.0in.; b=0.5 in.; c=0.25 inches; d=0.25 in.; e=0.5 in. Thus, when theelectrical box 10 nests within the second receiving section 52, theelectrical box 10 is extended about 0.75 inches (b+d). Therefore, theelectrical box 10 is extended to a wall thickness t₂ of about 1.25inches. Preferably, the drywall 54 a thickness in FIG. 5 will also besubstantially about t₂ or 1.25 inches. However, present electrical codesallow 0.25 in. of non-combustible drywall 54 materials to be exposedbeyond the electrical box 10, so the drywall 54 thickness may alsoextend up to 0.25 inches beyond the extension 30, effectively extendingthe electrical box 10 to about 1.50 inches.

ASSEMBLY & OPERATION

The electrical box 10 and extension 30 can accommodate a range ofdrywall 54 thicknesses of up to substantially about 1.5 inches or more.The electrical box 10 is preferably installed using the following steps.First, the electrical box 10 is fastened onto at least one joist ortruss utilizing a retaining screw. Electrical wires are then pulledthrough the electrical box 10 and positioned for attachment of theelectrical fixture.

Once the electrical box 10 is in place, drywall 54 is installed forforming a continuous ceiling or wall over the electrical box 10. Theelectrical box 10 abuts the drywall 54. Thus, proximate the location ofthe electrical box 10, the drywall 54 bulges outwardly. The electricalbox 10 is visible in the ceiling or wall by the bulge in the drywall 54.A conventional tool such as a router tool or saw is used to cut anopening 53 in the drywall 54 (alternatively, an aperture can be cut inthe drywall prior to installation). The circumference of the electricalbox 10 is used to guide the tool, thus defining a similarly shapedaperture in the drywall 54, which can be slightly larger than the outercircumference of the electrical box 10. Once the aperture is formed, thesurrounding drywall 54 returns to a flat position, no longer under thepressure from the electrical box 10, and at least part of the box isreceived in the aperture. The electrical box 10 and associated wiringare now exposed. A ceiling or wall finish is then applied. If theinstaller had not done it before, the installer now determines theamount or thickness of drywall 54 being utilized. At this point, theextension 30 is placed into opening 53 in the drywall 54 or the opening53 a in the drywall 54 a, and first receiving section 50 or the secondreceiving section 52 of the extension 30 are slidably attached to theouter wall 18 of the electrical box 10 through an interference fitdepending on whether the partially extended position (FIG. 3) or fullyextended position (FIG. 5) is desired. Lastly, the electrical fixture isattached and wired to the electrical box 10. Alternatively, rather thanhaving the electrical box 10 abut the drywall 54, an aperture can be cutin the drywall 54 prior to the installation steps set forth above andthe electrical box 10 can be received therein.

EMBODIMENT OF FIG. 6

An extension 100 according to a second embodiment of the invention isillustrated in FIG. 6. The extension 100 has a substantially H-shapedbase 102 with first leg 100 a, second leg 100 b, third leg 100 c, andfourth leg 100 d. Each leg 100 a–d has an inner wall 104 and an outerwall 106. Legs 100 a–d are integrally connected to one another by acentrally disposed flange 108. A substantially U-shaped first receivingsection 110 is formed between the first leg 100 a and second leg 100 b.A substantially U-shaped second receiving section 112 is formed betweenthe third leg 100 c and fourth leg 100 d. The first receiving section110 and the second receiving section 112 are formed on opposite sides ofthe centrally disposed flange 108. The first receiving section 110 has agreater depth then the depth of the second receiving section 112.

In this embodiment, as shown in FIG. 6, the side wall of the box 10 isreceived via an interference fit in one or the other of the U-shapedreceiving sections 110 or 112 of the extension 100.

EMBODIMENT OF FIG. 7

An extension 200 according to a third embodiment of the invention isillustrated in FIG. 7. The base 202 includes a substantially annularinner wall 204 and a substantially annular outer wall 206. The outerwall 206 establishes an interference fit with the inner wall 16 of theelectrical box 10. The inner wall 204 and outer wall 206 aresubstantially concentric to the central axis of the base 202 and havegenerally smooth surfaces. The inner wall 204 and outer wall 206 extendcontinuously between the top edge 208 and the bottom edge 210 defining acentral aperture 212. The aperture 212 is preferably substantiallyannular, however, the aperture 212 can be formed in the shaped of anypolygon or combination of polygons.

A metal or plastic flange 214 is disposed on the outer wall 206.Preferably, the flange 214 is substantially rectangular incross-section, however, the flange can be of any polygonal shape orcombination of polygonal shapes. The flange 214 has a first mountingsurface 216 and a second mounting surface 218. A substantially L-shapedengagement lip is formed between the first mounting surface 216 andsecond mounting surface 218 and the outer wall 206. A first receivingsection 220 is formed between the flange 214 and the outer wall 206having a first depth and a second receiving section 222 is formedbetween the flange 214 and the outer wall 206 having a second depth. Thefirst depth is greater than the second depth.

In this embodiment, as shown in FIG. 7, the side wall of the box 10 isreceived via an interference fit on the outer wall 206 of the extension200.

EMBODIMENT OF FIG. 8

An extension 300 having a base 302 according to a fourth embodiment ofthe invention is illustrated in FIG. 8. The extension 300 includes afastener member 306 attached to a flange 304 of the extension 300. Thefastener member 306 is preferably removably connected to base 302 by,for example, breaking or cutting the connection; however, fastenermember 306 may alternatively be connected to flange 304 via fasteners oradhesive. The fastener member 306 is provided with a retainer member 308(e.g., a fastener, clip, spring biased arms, etc.) for releasablyholding longer fasteners for use with the extension 300. The fastenermember 306 is preferably integrally connected to the flange 304 or base302. At the connection arms 310, 312, the fastener member 306 willfatigue and break upon application of force, so that the user can easilyremove the fastener member 306 from the extension 300 by hand.

While various embodiments have been chosen to illustrate the invention,it will be understood by those skilled in the art that various changesand modifications can be made therein without departing from the scopeof the invention as defined in the appended claims.

1. An extension adapted for use with an electrical ceiling box,comprising: a base including a first edge, a second edge, an inner wall,and an outer wall, said inner wall defining an aperture; a substantiallyannular flange disposed on said inner wall, said flange having first andsecond support surfaces; and a first receiving section formed betweensaid first edge and said first support surface, and a second receivingsection formed between said second edge and said second support surface.2. An extension according to claim 1, wherein said first receivingsection and said second receiving section have different depths.
 3. Anextension according to claim 2, wherein the depth of said firstreceiving section is greater than the depth of said second receivingsection.
 4. An extension according to claim 1, wherein a fastener holderis removably connected to said flange.
 5. An extension according toclaim 1, wherein a fastener holder is removably connected to said base.6. An extension according to claim 1, wherein said base is substantiallyannular.
 7. An extension according to claim 1, wherein said base has asubstantially uniform transverse cross section along an entire lengththereof.
 8. An extension according to claim 1, wherein said base andsaid flange are integrally connected.
 9. An extension according to claim1, wherein said base and said flange are made of a polymeric material.10. An electrical box assembly, comprising: a electrical box having aside wall including an inner surface and outer surface; an extensionhaving a base including a first edge, a second edge, an inner wall, andan outer wall, said inner wall defining an aperture; a flange disposedon one of said inner or outer walls having first and second supportsurfaces; and a first receiving section formed between said first edgeand first support surface, and a second receiving section formed betweensaid second edge and said second support surface, each receiving sectionhaving a different depth from one another, and being slidably engageablewith at least one surface of said electrical box for mounting saidelectrical box in either a partially extended position or a fullyextended position.
 11. An extension ring according to claim 10, whereinthe depth of said first receiving section is greater than the depth ofsaid second receiving section.
 12. An extension ring according to claim10, wherein the at least one surface of the electrical box is an outersurface.
 13. An extension ring according to claim 10, wherein the atleast one surface of the electrical box is an inner surface.
 14. Anextension ring according to claim 10, wherein the at least one surfaceof the electrical box comprises both the inner surface and the outersurface.
 15. An extension ring according to claim 10, wherein a fastenerholder is removably connected to said flange.
 16. An extension ringaccording to claim 10, wherein a fastener holder is removably connectedto said base.
 17. An extension ring according to claim 10, wherein saidbase and said flange are substantially annular.
 18. An extension ringaccording to claim 10, wherein said base has a substantially uniformtransverse cross section along an entire length thereof.
 19. Anextension ring according to claim 10, wherein said base and said flangeare integrally connected.
 20. An extension ring according to claim 10,wherein said base and said flange are made of a polymeric material. 21.A method of mounting an electrical box extension, comprising the stepsof connecting an electrical box to a support; installing a ceiling orwall adjacent the support; locating the electrical box in the ceiling orwall; cutting an aperture in the ceiling or wall for exposing theelectrical box; positioning one of a first receiving section or a secondreceiving section of an extension contiguous to the electrical boxdepending upon a thickness of the ceiling or wall, the first and secondreceiving sections having a different depth from one another; slidablyattaching the one of a first receiving section or a second receivingsection to at least one surface of the electrical box in either apartially extended or a fully extended position, the extension having aflange defining the inner ends of each of the first and second receivingsections and being spaced from the outer ends of each of the first andsecond receiving sections.
 22. A method of mounting an electrical boxextension according to claim 21, and further comprising the steps ofattaching an electrical fixture to the electrical box.
 23. A method ofmounting an electrical box extension according to claim 21, wherein theceiling or wall is comprised of drywall.